From dc1af0605f7685aff753ad7b6cd72a69309fa274 Mon Sep 17 00:00:00 2001
From: Bronek Kozicki <823856+Bronek@users.noreply.github.com>
Date: Thu, 12 Oct 2023 14:43:21 +0100
Subject: [PATCH] Switch to flat_multimap, minor improvements

---
 src/ripple/rpc/impl/Handler.cpp | 42 ++++++++++++++++++++-------------
 src/ripple/rpc/impl/Handler.h   |  2 +-
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/src/ripple/rpc/impl/Handler.cpp b/src/ripple/rpc/impl/Handler.cpp
index b7f0dace5e3..e460c7d7a9e 100644
--- a/src/ripple/rpc/impl/Handler.cpp
+++ b/src/ripple/rpc/impl/Handler.cpp
@@ -22,6 +22,8 @@
 #include <ripple/rpc/impl/Handler.h>
 #include <ripple/rpc/impl/RPCHelpers.h>
 
+#include <boost/container/flat_map.hpp>
+
 namespace ripple {
 namespace RPC {
 namespace {
@@ -57,6 +59,19 @@ handle(JsonContext& context, Object& object)
     return status;
 };
 
+template <typename HandlerImpl>
+Handler
+handlerFrom()
+{
+    return {
+        HandlerImpl::name,
+        &handle<Json::Value, HandlerImpl>,
+        HandlerImpl::role,
+        HandlerImpl::condition,
+        HandlerImpl::minApiVer,
+        HandlerImpl::maxApiVer};
+}
+
 Handler const handlerArray[]{
     // Some handlers not specified here are added to the table via addHandler()
     // Request-response methods
@@ -174,7 +189,8 @@ Handler const handlerArray[]{
 class HandlerTable
 {
 private:
-    using handler_table_t = std::multimap<std::string, Handler>;
+    using handler_table_t =
+        boost::container::flat_multimap<std::string, Handler>;
 
     // Use with equal_range to enforce that API range of a newly added handler
     // does not overlap with API range of an existing handler with same name
@@ -244,15 +260,15 @@ class HandlerTable
     std::vector<char const*>
     getHandlerNames() const
     {
-        static constexpr auto less = [](const char* const lh,
-                                        const char* const rh) -> bool {
-            return std::strcmp(lh, rh);
-        };
-        std::set<const char* const, decltype(less)> names;
+        std::vector<char const*> ret;
         for (auto const& i : table_)
-            names.insert(i.second.name_);
+        {
+            // Note, table_ is always ordered, allowing such a simple check
+            if (ret.empty() || std::strcmp(ret.back(), i.second.name_) != 0)
+                ret.push_back(i.second.name_);
+        }
 
-        return std::vector<char const*>{names.begin(), names.end()};
+        return ret;
     }
 
 private:
@@ -270,15 +286,7 @@ class HandlerTable
             HandlerImpl::minApiVer,
             HandlerImpl::maxApiVer));
 
-        Handler h;
-        h.name_ = HandlerImpl::name;
-        h.valueMethod_ = &handle<Json::Value, HandlerImpl>;
-        h.role_ = HandlerImpl::role;
-        h.condition_ = HandlerImpl::condition;
-        h.minApiVer_ = HandlerImpl::minApiVer;
-        h.maxApiVer_ = HandlerImpl::maxApiVer;
-
-        table_.insert({HandlerImpl::name, h});
+        table_.insert({HandlerImpl::name, handlerFrom<HandlerImpl>()});
     }
 };
 
diff --git a/src/ripple/rpc/impl/Handler.h b/src/ripple/rpc/impl/Handler.h
index eafc165a60f..9c4008bb6e7 100644
--- a/src/ripple/rpc/impl/Handler.h
+++ b/src/ripple/rpc/impl/Handler.h
@@ -55,7 +55,7 @@ struct Handler
     RPC::Condition condition_;
 
     unsigned minApiVer_ = 1;
-    unsigned maxApiVer_ = RPC::apiMaximumValidVersion;
+    unsigned maxApiVer_ = apiMaximumValidVersion;
 };
 
 Handler const*